Abstract：The behavior of rock block on a macro-scale is described by the classical mechanics of continuum，while the discontinuous displacement field between rock blocks is represented by a combination of smooth functions，which characterizes the deformational behavior of rock block interfaces. Hence，the way is mathematically described in which the energy is stored，dissipated and transferred between rock block interfaces. In the context of the proposed procedure，taking the determination of rock pressures on a circular tunnel for example，the proportion of pressures around the tunnel resisted by each zone is calculated based on a simplified stress-slip displacement relation；the direct relationships among the rock pressures and the buried depth，dimensions and shape of the tunnel，the physico-mechanical characteristics of rock mass，and the flexibility of supports and etc.，are illustrated.
